Topical sodium bicarbonate: No improvement in blood buffering capacity or exercise performance

Purpose: To assess the efficacy of a topical sodium bicarbonate (0.3 g/kg body weight NaHCO₃) application (PR lotion; Amp Human) on blood buffering capacity and performance in recreationally active participants (study A) and moderately trained athletes (study B). Methods: In Study A, 10 participants completed 2 experimental trials: oral NaHCO₃ (0.3 g/kg body weight + placebo lotion) or PR lotion (0.9036 g/kg body weight + oral placebo) applied 90 minutes prior to a cycling task to exhaustion (30-s sprints at 120% peak power output with 30-s rest). Capillary blood was collected and analyzed for pH, bicarbonate, and lactate every 10 minutes throughout the 90-minute loading period and postexercise at 5, 10, and 15 minutes. In Study B, 10 cyclists/triathletes completed 2 experimental trials, applying either PR or placebo lotion 30 minutes prior to a cycling performance task (3 × 30-s maximal sprints with 90-s recovery). Capillary blood samples were collected at baseline, preexercise, and postexercise and analyzed as per study A. Results: In Study A, pH and bicarbonate were significantly elevated from baseline after 10 minutes in the oral NaHCO₃ condition and throughout recovery compared with no elevation in the PR lotion condition (P <.001). No differences in cycling time occurred between PR lotion (349 [119] s) and oral NaHCO₃ (363 [80] s; P =.697). In Study B, no differences in blood parameters, mean power (P =.108), or peak power (P =.448) were observed between conditions. Conclusions: PR lotion was ineffective in altering blood buffering capacity or enhancing performance in either trained or untrained individuals.